The present invention relates to specimen grips and more particularly to a multi-functional hydraulic grip which provides rapid assembly or disassembly of the components for facilitating the replacement of the grip jaws thereon and which the hydraulic system has double conduits and is alterable for a cooling system during a specimen testing in high temperature.
Prior art hydraulic specimen grips vary in form and have been advanced as the time being. The most typical specimen grips adapted to tension testing are the horizontal movement, of the jaws relative to the specimen. The jaws have their outward wedge surface in front of the camming surface of an outer gripping housing. Thereby when the outer grip housing is actuated to move vertically by hydraulic pressure, the camming surface moves the jaws horizontally toward each other so as to grip a specimen therebetween. The outer gripping housing may be enclosed or partially opened in order to permit a specimen to be loaded longitudinally or laterally. However. These types of specimen grip have the same disadvantages outlined as follows:
a) They cannot obviate mechanical oscillation because the outer grip housing is urged back up in normal place by springs when the hydraulic pressure is released, especially when some of those springs are weakened because of metallic fatigue that causes unbalanced backward movement. PA1 b) These specimen grips have their jaws slidingly mounted on their laterally protrudent shanks into a T-slot of a mounting body assembly that appears clearances therein, therefore causing unstable movement of the jaws. PA1 c) These specimen grips are operated solely depending on hydraulic pressure via a single conduit without any alteration that presents an operational limit especially when the testing of a specimen is performed in high temperature.